Gas sensors attached to inlet systems or exhaust systems of internal combustion engines (for example, diesel engines or gasoline engines) are known. Such a gas sensor is used to detect the concentration of a specific gas component (for example, oxygen or Nox) contained in measurement target gas (see, for example, PTL 1). The gas sensor disclosed in PTL 1 includes a detector element that extends in an axial direction, connection terminals, and a separator. The detector element includes a detection portion that is disposed at a front side and through which a current corresponding to the oxygen concentration flows and electrical pads that are disposed at a back side and that are in contact with the connection terminals. Each connection terminal includes a frame main body that extends in the axial direction, a contacting portion that extends from a back end portion of the frame main body toward the back side and that is in contact with a conductive member, and an element contact portion that is bent at a front end portion of the frame main body so as to extend toward the back side and that is in elastic contact with a corresponding one of the electrical pads. The conductive member is electrically connected to an external circuit for calculating a specific gas component on the basis of a signal output from the detector element. The separator accommodates at least a portion of each connection terminal and at least a back portion of the detector element.